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L. BAUMANN, 8a., AND F. BAUMANN. TOOL FOR CURING G UN FORGINGS AND SHAFHNG.

APPLICATION FILED OCT 24. I918.

Y Patented July 15, 1919.

2 SHEETS-SHEET i.

L. BAUMANN, 8a.. TOOL FOR CORING UN APPLICATION r1 ANDF BAUMANN FORGINGS AND SHAFTING.

- 1,310,319. I "m. PatentedJuly 15,1919.

2 SHEETSSHEET 2- Ill v N Z..."-

A A UITED $TATES A PATENT OFFICE.

V LEoroLD'BAUMANN, sa, AND EEEDEEIcK BAUMANN, E PHILADELPHIA, PENN- SYLVANIA, ASSIGNORS oE sEvEN THIRTY-SECONDS TO sAID LEOPOLD BAU- MANN, sn, sEvEN THIRTY-SECONDS T0 SAID EEEDEEIcK BAUMANN, AND

SEVEN .TI-IIRTY-SECONDSTO NORMAN T. WHITAKER AND.ELEVEN THIRTY- SECONDS T0 HERBERT J. BROWNE, BOTH; OF WASHINGTON, DISTRICT OF C0- LUMBIA.

To all whom it may concern:

Be it known-that we, LEoroLn BAUMANN,

Improvements in Tools for Goring 'Gun Forgings and Shafting, of which the follow-.

ing isa specification.

Thls lnvention relates to tools for coring gun-forgings and shat-ting althoughjnot re stricted to such use. j j

An important object of the invention 13 to A provide in a too-1 of the above mentioned character a means whereby'the strain of rotation exerted during a coring operation may be so distributed as to renderthe tool capable of withstanding any strain imparted to the same durin its period of operation, and means for obviating the vibration of the tool during the operation thereof, thereby insuring the maximum accuracy. c

A further object of this invention is to provide in a tool of the character hereinbefore stated, a means whereby a minimum amount of metal is removed in the form of valueless chips but the major portion of the core. j 7

Another object of the invention is to provide in a tool of the above mentioned char acter a means whereby the material lying in the path'of the cutting element may be grooved immediately priorto the removal of the same by this cutting element, thus reducing the size of the cuttings inorder to permit them to p'assfreely from the bore without clogging or obstructing the passage through which they are ejected.

A further object of the invention is to pro vide in a tool ofthe character described a means whereby the cutting edges of. the various cutting elements employed may be maintained in a radial position with respect to the axis of thetool in order that the strain metal is removedin the form of a valuable TOOL FOR CORING GUN FORGINGS AND SHAFTING.

Specification of Letters Patent. Patented July 15, 1919. Application filed October 24, 191s. Serial No. 259,556.

of rotation may be at all times exerted perpendicularly to the radii common to the cutting edges of said tools, thereby eliminating any tendency of the tool to lead ofl? during its operation.

A further object of the invention is to provide in a tool of the above mentioned character a means whereby a free vertical vibration of the core may be permitted during the operation of thesame.

A still further object of the invention is to provide in a tool of the above mentioned character a means whereby the cutting end of the tool may be reinforced against wear resulting fro'mthe contact thereof with the metal upon which the tool is operating.

A further object of the invention is to providein' a tool of the above mentioned character a. means whereby a suitable cooling agent or lubricant maybe regularly and constantly employed in connection with the same in order to maintain a normal temperature within the device and throughout the material which is desired to be operated upon. v

A further object of the invention is to provide in a tool of the above mentioned character a means whereby the cooling agent or lubricant employed may be utilized as a means for ejecting the cuttings obtained during the coring operation from the path of travel of the tool. A

A further object is to provide in a tool of the above mentioned character a means for facilitating the removal of the cooling agent or lubricant together with the cuttings carried thereby from the path of travel of the too Another object of the invention is to provide in a tool of the character hereinbefore disclosed, a means whereby a primary bore may be enlarged or counter-bored during the same cutting operation that forms the initial or primary bore.

further object is to provide a tool of the above mentioned character which is simple in construction, inexpensive to manufacture, effective in use, and reliable in operation,

Other objects and advantages of this 1nvention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate llke parts throughout the same,

Figure 1 is a side elevation of the tool embodying our invention,

Fig. 2 is a horizontal longitudinal sectional view of a gun-forging showing the same mounted within a lathe and as being operated upon by the tool embodying our invention, the tool being shown in top plan,

Fig. 3 is an end elevation of the tool, parts appearing in section,

Fig. i is an end elevation of the tool depicting a plurality of grooving elements applied thereto, parts appearing in section,

Fig. 5 is a detailed elevation of a grooving element, the grooving element being shown as secured within the end of the tool,

Fig. 6 is an enlarged detail fragmental sectional view of a portion of a forging showing diagrammatically a plurality of grooves formed therein,

Fig. 7 is a perspective view of a grooving element, and

Fig. 8 is a perspective view of a modified form of grooving element.

In the drawings, wherein for the purpose of illustration is shown a preferred form of our invention, the numeral 10 indicates a lathe having a chuck 1.1 within which the work such as a gun-forging or shafting 12 of any form desired to be operated upon is centrally secured.

To a suitable portion, not shown, of the lathe 10 there is secured the tool embodying our invention, which tool is indicated as a whole by the numeral 13 and comprises a shank 11. To the shank 14 there is connected a head 15, which head carries an elongated segmental shell 16, which shell is provided at one end thereof with an offset or hearing portion 17. Within the offset 17 there is arranged a plurality of bearing strips 18, the bearing strips bein dove-tail as clearly shown in Fig. 3 and formed of a relatively harder metal than the bearing portion 17. The strips 18 may be secured in their relative positions by means of set screws or the like 19 and are adapted to be easily removed to permit the insertion of new ones. By this arrangement of wear strips it has been found that excessive wear upon the offset or bearing portion may be relieved when such wear strips are formed from a relatively harder metal-than the offset or bearing portion 17. Upon one face of the segmental shell 16 there is arranged a cutting element 18 which is provided with a 26 is rectangular in cross section.

tongue 19 adapted to seat within a groove 20, the groove 20 being formed within the shell 16 as clearly shown in Fig. The tongue 19 and groove 20 preferably extend throughout the entire length of the cutting element 18 and they together with set screws 21 are adapted to retain the cutting element 18 always in a desired position with respect to the shell 16. In actual practice it has been found necessary, in order to insure an accurate cutting during the operation of the tool, that the cutting edge 22 of the cutting element 18 be arranged radially with respect to the center of curvature of the segmental shell 16. In Fig. 3 the radius of curvature of the segmental shell 16 is indicated by the character 7, which radius it is apparent is common to the cutting edge 22 of the cutting element 18.

In actual practice it has been found desirous in many instances that the shell have an arc ofappreciably more than 180 and it has further been found by experiment that the core 23 obtained by the operation of the tool partakes of a vertical vibratory move ment during the operation. In order to permit a free vibration of the core 23 and thereby eliminating any vibratory movement of the shell 16 which would Otherwise be imparted thereto it has been found necessary that the inner wall of the shell 16 be slightly flattenedtas shown at 24.

By experiment it has been discovered that a more effective and faster cutting of the tool 18 may be attained if one or more grooves is cut. in the path of travel immediately prior to the cutting of the too-l 18. It has further been found, by cutting one or more grooves, that the cuttings or chips obtained by the tool 18 are removed in a splitcondition or in finer particles and as a result of this splitting or breaking up of the chips they are more easily ejected from the bore of the forging or other material operated upon. As a means for cutting a groove immediately prior to the cutting of the cutting element 18 we employ a grooving element 25 which comprises a shank 26 having a cutting point 29, which cutting point preferably extends slightly deeper into the ma:

terial operated upon than the cutting ele ment 18. If it is desired to form a plurality of grooves as above described a plurality of grooving elements may be employed and arranged with respect to each other as clearly shown in Fig. 4. In Fig. 8 we have shown a slightly modified form of grooving element 25, it differing from the grooving element hereinbefore described only in that the shank As a means for retaining the grooving elements in position we preferably employ set screws 28 as clearly shown in Fig. 5.

When considering Fig. 4 it will be noted that the cutting faces 27 of the cutting points 329' are arranged radially with're- V spect to the .center ofcurvature of theshell 16, the radial line 9" being shown as common to the cutting points 29. In actual practice it has been found essential that the cutting points 29 bearrangedradially with respect to the centerbf curvature of the shell 16 as above described in order to insure an accurate operation of the tool. When considering Fig. 6 it is apparentthat the portions of the metal lying between the grooves v30 formed by the grooving elements 25 will be removed independently of each other since the cutting element 18 does not make a cut so deep as the cutting points 29 of the grooving elements 25. Since these portions are removed independently of each other it will be readily understood that the chips obtained by the cutting element 18, being finer particles than would otherwise be, may be more readily ejected from the bore of the material such as a gun-forging or shafting 12.

As a means for ejecting chips from the bore of the material or gun-forging 12 we employ a liquid supply pipe 31 which is secured upon one edge of the shell 16 by means of clamps 32. This pipe is adapted to be connected to a suitable source of liquid such as soapy water, which liquid is adapted not only to facilitate the removal of the cuttings but also to prevent the cutting element 18 from overheating during the operation. The end of this pipe is bent to an arcuate shape as clearly shown in Figs. 3 and 4 and has its open end arranged in proximity to the cutting tool 18. Upon the liquid supply pipe 31 there is imposed an air supply pipe 33, the air supply pipe 33 being adapted for connection with a suitable source of air pressure, not shown, and secured in position by means of a plurality of clamps 34. substantially identical with those indicated by the numeral 32. The air supply pipe 33 extends substantially throughout the length of the shell 16 and has its end bent to anarcuate shape as shown at 35. The end of the arcuate shaped portion 35 is bent to a parallel position with respect to the pipe 31 as shown at 36 in order that a supply of air may be directed outwardly from the bore, thereby facilitating the removal of the liquid together with the cuttings or chips obtained by the cutting element 18. Although these pipes are illustrated and described as being secured to the tool by clips, this structure is not mandatory but is only indicative of one means of assembly. In conditions where soldering would prove advantageous this means of securing the pipes to the tool may be resorted to within the scope of the invention.

Provision is made in this tool forenlarging the initial or primary bore for any preferred portion of its length. This is accomplished by enlarging or increasing the diameter of the shell 16 intermediate its terminals, thereby forming a transverse shoulder 41. A longitudinal groove 39 is provided in this enlarged portion of the shell 16 for the reception of a tongue 38 extending from a secondaryor auxiliary cutting element 37. The secondary cut-ting element 37 is secured to the enlarged portion of the shell 16 by set screws40. The secondary cutter 37 may be secured to the shoulder 41 formed at any preferred point on the shell 16 relative to its length, this position being determined by the length that itis desired to make the e11- larged how.

The operation of the device is as follows:

Th cutting element 18 and grooving points 29 of the tool 13 are brought into engagement with the rotating work such as a gun-forging or shafting 12 whereupon a core 23 is formed, which core in diameter is substantially equal to the inner diameter of the shell 16. As the work or gun-forging or shafting 12 is rotated with respect to the tool 13 one or more grooves are formed in the path of travel of the cutting element 18 as shown in Fig. 6, the grooves being formed by the cutting edge or point 29 of the grooving element 25. It is apparent therefore from Fig. 6, since the cutting point 29 makes a deeper out than the cutting element 18, that the chips obtained by the cutting element 18 are reduced to fine particles and because of this splitting or reduction to particles the chips may be removed from the bore of the work without becoming lodged therein. During the operation of the tool preferably soapy water is injected into the bore of the forging or other work through pipe 31, the liquid serving as a cooling agent, as a lubricant, and as a means for ejecting the chips from the bore of the forging. In order to facilitate the removal of liquid from the bore, air is injected into the bore through the pipe 33, the air being released or ejected from the pipe 33 through the bent portion 36 in an opposite direction to the advancing movement of the tool 13.

If it is desired to enlarge the bore for any desired length the cutter 37 is secured in position. This tool will engage the wall of shell the inner curved surface of which constitutes an are greater than 180, said inner surface being flattened to permit a vibratory movement of the core, and a cutting 5 element carried by said shell.

2. A device of the character described comprising a segmental shell, a cutting element carried by said shell, and a second cutting element secured to said shell intermediate its ends and having its cutting edge ex- 10 tending radially from said shell.

LEOPOLD BAUMANN, 'sR. FREDERICK BAUMANN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 01 Patents,

Washington, D. 0. 

